[CommandsTests] Disable a tsan test
[CommandsTests] Disable a tsan test

For some reason this test is failing on swift 4.2 branch but not on
trunk. Need to investigate.

https://bugs.swift.org/browse/SR-7272

JGiola/swift-package-manager,JGiola/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager,sschiau/swift-package-manager,sschiau/swift-package-manager,JGiola/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,JGiola/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,JGiola/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,sschiau/swift-package-manager,sschiau/swift-package-manager,sschiau/swift-package-manager